Obstruction removal apparatus

ABSTRACT

A device for extracting obstructions from confined spaces includes a flexible outer shaft movable relative to an inner central member. The central member is attached to the outer shaft and in a first embodiment, contains one or more teeth or claws. Upon insertion of the device into an obstructed space, the claws are retracted inside the shaft for easy passage past the obstruction. During withdrawal of the device from the space, the claws become extended beyond the outer shaft, thereby facilitating positive engagement of the obstruction. In an alternative embodiment, the claws are replaced by one or more sections of the outer shaft having longitudinal slits or striations. During insertion of the device, the slitted sections are expanded longitudinally, narrowing these sections for easy passage into the pipe. During withdrawal, the sections are longitudinally compressed, resulting in their radial expansion or bellowing, and enabling engagement of the obstruction.

United States Patent 1 Strom 1 1 OBSTRUCTION REMOVAL APPARATUS MartinStrom, 261-01 69th Ave., Floral Park, L.l., N.Y.

[22] Filed: Aug. 18, 1971 1211 Appl. N0.: 172,749

[76] Inventor:

Primary ExaminerEdward L. Roberts Attorney-Barry H. Freedman ABSTRACT Adevice for extracting obstructions from confined spaces includes aflexible outer shaft movable relative to an inner central member. Thecentral member is attached to the outer shaft and in a first embodiment,contains one or more teeth or claws. Upon insertion of the device intoan obstructed space, the claws are retracted inside the shaft for'easypassage past the obstruction. During withdrawal of the device from thespace, the claws become extended beyond the outer shaft, therebyfacilitating positive engagement of the obstruction. In an alternativeembodiment, the claws are replaced by one or more sections of the outershaft having longitudinal slits or striations. During insertion of thedevice, the slitted sections are expanded longitudinally, narrowingthese sections for easy passage into the pipe. During withdrawal, thesections are longitudinally compressed, resulting in their radialexpansion or bellowing, and enabling engagement of the obstruction.

34 Claims, 10 Drawing Figures PAIENIEDSEPI 1 m8 SHEEI 1 [IF 2 lNl/E/VTORMART/N STROM PNENTED SEPI I I975 SHEET 2 [IF 2 u I Wm J m w 8 S a 1OBSTRUCTION REMOVAL APPARATUS BACKGROUND OF THE INVENTION Sewer snakesand other devices heretofore known in' the prior art for removingobstructions from confined spaces have usually comprised flexible shaftsformed of a spiral wire having affixed at their leading ends a hook,claw, or other attachment intended to impale or dislodge theobstruction. The successful operation of such devices has been limited,however, because the teeth or claws themselves impede insertion of thedevice into pipes or other confined spaces having bends or turnstherein. These devices have also posed problems because of their randomor non-positive action in engaging obstructions of unknown shapes andsubstances. In many cases, the use of prior art devices has resultedinmerely pushing the foreign object further down the pipe or duct, whereit becomes lodged more firmly and still more difficult to remove.Oftentimes, disassembly of an obstructed portion of a pipe may then benecessitated, with the attendant consumption of a good deal of time andeffort. Where the obstruction is located within a body duct or vessel,surgery may then be required.

To attempt to overcome these difficulties, other prior art devices haveemployed retractable grappling members which are held within a flexibleshaft during its insertion into a pipe or other confined space, therebyreducing the tendency of the claws or teeth'to resist insertion of thedevice. In such prior art devices, however, the grappling member istypically actuated by the application of a pushing force on a wire whichholds the grappling member in place. Where the obstruction is firmlylodged within the pipe, such a manipulation may be insufficient toactuate the claws, sincerthe pushing force exerted on the inner wire isnot easily transmitted to the grappling member. In this event, the wiremay merely become deformed and of no'further use. In addition, theconfiguration of such devices precludes the attachment of cutting toolsto the leading end of the apparatus, where the retractablegrapplingmember is situated. Also, the types of handles or extension devices thatmay beattached to the trailing end of the apparatus is restricted, sinceprovision must always be made for the grappling member control wire.

In view of the aforementioned difficulties associated with prior artsnake-like devices, it is the broad object of the present invention toprovide an improved device that is uncomplicated and inexpensive toconstruct, simple to operate, and likely to positively engage and removeforeign objects from confined spaces.

A further object of the invention is the provision of such a devicecapable of fabrication from a variety of materials and in numerouslengths and sizes,'enabling its use in such diverse fields as plumbingand surgery, and in any other field wherein foreign objects must bepositively engaged and removed from confined spaces of various kinds.

Yet another object of the invention is the provision of an obstructionextraction device capable of carrying a variety of cutting tools at itsdistal end, and a handle or extension device at its proximal end, inaddition to, and without impeding the operation of, a plurality ofclaw-like protrusions designed to positively engage the obstruction bytheir extension from the body of the device.

An additional object of the invention is the provision of a device forgenerally cleaning the interior portions of elongated tubes or ductsthat advantageously utilizes friction forces generated between the outershaft of the device and the interior duct surfaces to longitudinallydisplace the outer shaft with respect to an inner central memberattached to the outer shaft, so that one or more claws responsive to thelongitudinal displacement are radially retracted during insertion of thedevice and radially extended during withdrawal of the device from theduct.

SUMMARY OF THE INVENTION The present invention avoids the previouslymentioned difficulties of prior art snake-like devices, and meets theabove stated and other objects, by the provision of an obstructionextraction apparatus wherein one or more claws or teeth designed toremove obstructions from and generally clean the interior of a pipe,duct, or other confined space, are automatically retracted toward orinto, or extended from, the body of the device by friction forcesexerted on the device during its insertion and withdrawal, respectively,from a confined area.

More specifically, there is provided in a first embodiment of theinvention a tool or device of the type described which includes aflexible outer shaft of coiled wire or other suitable material, and aninner central member of solid or stranded wire or the like, fastened tooneor both ends of the outer coil. The outer shaft is comprised of atightly coiled, relatively long center section, and one or two looselycoiled, relatively short other confined space produces friction forcesbetween the outer shaft and the inner walls of the pipe, tending torearwardly displace the outer shaft relative to the in'ner centralmember. As a result of the relative'motion, the teeth or claws attachedto the inner central member are retracted into or covered by the outershaft. Accordingly, insertion of the device can proceed, unimpeded bythe resistance of the claws. Upon withdrawal of the device from thepipe, friction forces are reversed, as is the direction of relativemotion between the inner central member and the outer shaft. The teethor claws attached to the inner central member are extended from theouter shaft, and are in a suitable position to easily engage and removean obstruction lodged within the pipe.

In an alternative embodiment, the previously mentioned claws arereplaced by one or more sections of a hollow tubular outer shaft havinglongitudinal slits or striations that enable longitudinal compression'ofthe sections. During insertion of the device, the previously mentionedfriction forces acting between the outer shaft and the inner walls ofthe duct being cleaned serve to elongate and therefore constrict theslitted section, permitting easy passage of the device past anobstruction. During withdrawal, when friction forces are reversed, theslitted sections are longitudinally compressed, resulting in theirradial expansion or bellowing. The portion of the slitted sections ofthe outer shaft that are thus radially extended act in much the samemanner as the aforementioned claws in enabling positive engagement andremoval of the foreign article.

As is apparent from the preceeding description, the above stated andother problems of prior art devices of the type described are obviated,and the stated and other objects are attained, by the provision of adevice in accordance with the principles of the instant invention.Positive engagement of an obstructing article is enabled by theautomatic extension of teeth or claws from the body of the device duringits withdrawal from a pipe or duct. Impediment to the insertion of thedevice is minimized by the retraction of the teeth or claws duringinsertion of the device into a pipe or other confined space.-Inaddition, since the teeth are extended from the body of the device, itsleading end may be adapted to carry a variety of cutting or cleaningimplements that may further serve to facilitate its operation, while thetrailing end may similarly be arranged to permit engagement with ahandle or an extender apparatus. Also, it is'to be observed that apulling rather than a pushing force is utilized to extend the teeth orclaws into engaging position, thereby eliminating a source of difficultyin prior art devices.

BRIEF DESCRIPTION OF THE DRAWING The above stated and other aspects andfeatures of the invention may be more easily understood and appreciatedfrom a consideration of the following detailed description when read inlight of the accompanying drawing, in which:

FIG. 1 is a partially cut-away view, in elevation, of a first embodimentof a device in accordance with the principles of the invention, shown inits static condition;

FIG. 2 is an enlarged view, in elevation, of the leading portion of thedevice of FIG. 1, during its insertion into a pipe or other'confinedspace;

FIG. 3 is a view similar to FIG. 2, showing the leading portion of thedevice during its withdrawal from a pipe or other confined space;

FIG. 4 is a view in elevation illustrating a cleaning device constructedin accordance with the principles of the invention in position forremoving an obstruction from a curved pipe section, diagrammaticallyindicated by broken lines;

FIG. 5 is a partially cut-away view, in elevation, of an alternateembodiment of a device in accordance with the principles of theinvention, shown in its static condition;

FIG. 6 is a view, in elevation, of the device of FIG. 5 during itsinsertion into a pipe or other confined space;

FIG. 7 is a view similar to FIG. 6 showing the device during itswithdrawal from a pipe or other confined space;

FIG. 8A is an edge view of one portion of the device of FIG. 5, in itsstatic condition; and

FIGS. 88 and 8C are edge views similar to FIG. 8A of the same portion ofthe device during withdrawal and insertion, respectively.

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. 1, there isshown one embodiment of an obstruction removing device in accordancewith the principles of the invention, comprising a hollow outer shaftdesignated generally as 10, an inner central member or rod 11, and oneor more teeth or claws, such as claws 12 and 12'.

Outer shaft 10, which may be fabricated from a single helically coiledstrand of metal or plastic wire or any other material possessingsuitable characteristics of strength and flexibility, includes threesections, 10a, 10b, and 106. Section 10a, which is relatively long incomparison to the remaining sections, is arranged so that adjacent coilsare in close proximity to each other, and is generally located at thecenter of outer shaft 10. Sections 10b and 10c, which are relativelyshort in comparison to center section 10a, are located toward each endof outer shaft 10, and arranged so that adjacent convolutions are spacedapart with respect to one another, thereby permitting compression ofthese sections upon application of a longitudinally directed force.Additional closely wound sections 10d, 1014, may be located outwardlyfrom either or from both loosely wound sections 10b,-10c, but are notrequired in order to obtain satisfactory results in practising theinvention. The outer circumference of outer shaft 10 is arranged to besmaller than the inner circumference of the pipe to be cleaned, therebypermitting insertion of the device into the pipe.

Inner central member 11, which may be fabricated from a single ormulti-stranded wire of metal, plastic, or other suitable material, isarranged to have a length at least substantially equal to that of outershaft 10, when the latter is in its static condition, and an outerdiameter smaller than the inner diameter of outer shaft 10. Innercentral member 11 may be straight, as shown in FIG. 1, or may behelically coiled, if desired.

Outer shaft 10 is fitted around inner central member 11, duringassembly, and fastened to each end thereof. Fastening may beaccomplished by means of annular washers 13, 14, having an outerdiameter substantially equal to that of outer shaft 10 and an annuluspermitting extension'of a small length of inner central member 11therethrough. The washers may be attached to the endmost coils of outershaft 10 by welding or other means, and the extension of central member11 may be attached to the annular washers 13, 14, also by welding. Ofcourse, other methods of-fastening may readily be devised by thoseskilled in the an; and are intended to be within the scope of theinvention.

Either or both washers l3, 14 may be formed as part of, or have attachedthereto, fittings 15, 16, respectively, which may be provided withexternally or inter coil shaped leading extremity that may on occasionbe useful in ensnaring certain obstructions. A handle may be attached tofitting 15, thus providing a comfortable means of gripping the device,or the entire device of FIG. 1 may be attached to the front end of aconventional coiled snake, thereby extending the range of the apparatusto include confined spaces far removed from an initial point of entry.

Fastened to inner central member 11 are one or more claws I2 and 12,which may be fabricated from a sin gle or stranded plastic or metalwire, or from any other material suitable for the purpose. As shown inFIGS. 1 and 3, the claws are preferably attached to inner central member11 at a point forward of, or toward the front of, section c of outershaft 10, although it may be advantageous especially in the case whereinner central member 11 consists of a stranded wire, to simply doubleback all or some of the strands from the attachment point at washer l4.Claws i2 and 12' are arranged to extend outwardly from inner centralmember 11 at a generally acute angle to the rear portion of the device,the free ends or tips of the claws protruding from outer shaft 10 at apoint toward the rearmost end of section 10c. The length of claws l2 and12 is selected such that, in the static condition of the device, thedisplacement D between their free ends and outer shaft 10 is maintainedrelatively small in comparison to the diameter of outer shaft 10. Wheremore than a single claw or tooth is employed, they are preferablyarranged to be spaced substantially equally around the circumference ofouter shaft 10. The tips or extremities of claws l2 and 12 may be curvedoutwardly from shaft 10, as shown'in FIG. 1, or may be inwardly curvedas is tooth 12a shown in FIG. 3. Straight, knobbed, or barb-tipped teethmay also be employed, depending upon the circumstances involved, thelatter also being illustrated by claw 12b of FIG. 3.

Operation of the device of FIG. 1 may best be appreciated with referenceto FIG. 4, which illustrates diagrammatically an S shaped pipe section40, quite common in the plumbing field and typical of pipe sections ofother shapes, into which the device may be inserted in order to removean obstruction.

As shown in FIG. 4, section 10a of outer shaft 10 makes contact with theinterior walls of pipe section 40 at several points, such as points 41and 42, due to the tendency of the device to maintain its naturallystraight condition, rather than conform to the curvature of the pipe.When the device is put in motion, friction forces F, and F, aregenerated at contact points 41 and 42, respectively, and act in adirection opposite to the direction of motion. Thus, if outer shaft 10is moving into pipe section 40, friction forces F, and F, act on theshaft in a rearward direction. Since these friction forces are, however,exerted only on outer shaft 10, and not on inner central member II,because'the latter is not brought in contact with the pipe walls, thereresults a rearward displacement of outer shaft 10 through thecompression of loosely coiled section 10b and the expansion of looselycoiled section 10c. Stated differently, friction forces acting only onthe outer shaft cause a point P on inner central member 11 to bedisplaced further, in the direction of motion, than a correspondingpoint Q on outer shaft 10, as can be seen by comparing the positions ofthose reference points in FIGS. 1 and 2, the latter of which depicts thecondition of section 10c of outer shaft 10 during insertion of thedevice.

Since claws l2 and 12 are attached to inner central member 111, they tooare correspondingly displaced longitudinally in relation to outer shaft10 during insertion. As shown in FIG. 2, the displacement D between thefree ends of claws l2 and 12 is reduced or virtually eliminated, sincethe relative movement between inner member I]. and outer shaft 10 actsto withdraw or retract the claws into outer shaft 10. Easy insertion ofthe entire device into pipe section 40, and past an obstruction or areato be cleaned, is thereby facilitated, since the resistance offered bythe claws is removed.

During withdrawal of the device from pipe section 40, friction forces F,and F are reversed in direction. Accordingly, loosely coiled section iscompressed, and loosely coiled section 10b is expanded, or, statedanother way, reference point P on inner central member 11 is nowrearwardly displaced further than corresponding reference point Q onouter shaft 10, as shown in FIG. 3. As a result, claws 12 and 12 areextended from outer shaft 10, increasing the displacement D between thefree ends of claws 12 and 12' and outer shaft 10. The claws are now inan advantageous position to positively engage a foreign object lodged inthe pipe, or to generally clean the interior of the pipe or duct.

Although the device of FIG. 1 is equipped with means for attaching innercentral member 11 to both ends of outer shaft 10, it is to be understoodthat attachment at only a single point, which becomes the functional endof the device, also permits satisfactory operation. For example, washerl3 and fitting 15 may be eliminated, and the proximal end of innercentral member 11 extended to form a handle or gripping means for thedevice, leaving outer shaft 10 attached to inner central'member 11 onlyat the distal end. In this event, expansion and compression of looselycoiled section 10c occurs as a result of device insertion andwithdrawal, respectively, as previously explained, and claws 12 and 12'are thus automatically retracted and extended. Since, in thisconfiguration, the proximal end of outer shaft 10 is free to move withrespect to inner central member 1 l, loosely coiled section 10b is notrequired.

In still another alternate configuration, washer 14 and fitting 16 maybe eliminated from the device of FIG. 1, leaving outer shaft 10 attachedto inner central member 11 at only the proximal end,without reducing theoperational capability of the apparatus. Insertion and retraction ofclaws 12 and 12, in; this event, is brought about by the relativemovement of outer shaft 10 with respect to inner central member '1 l, aspreviously explained. Since section 10c of outer shaft 10 is' notattached to inner central member 11 in this configuration, it does notbecome expanded or compressed during insertion and withdrawal, and isprovided only to permit protrusion of the extremities of claws l2 and 12through the coils of outer shaft 10.

An alternate configuration of adevice embodying the principles of theinstant invention is illustrated in FIG. 5, in its static condition. Thedevice includes a hollow tubular outer shaft, designated generally at50, and an inner central rod-like member 51 positioned inside the outershaft. Member 51 is shown attached to outer shaft 50 at both ends of thedevice, via washers 52 and 53, but as will be explained hereinafter,attachment at only a single end may occasionally be desirable.

Toward each end of outer shaft 50, which may be fabricated from a hollowcylindrical length of plastic tubing possessing suitable characteristicsof strength and flexibility, are one or more compressible sections, suchas sections generally indicated at 54 and 55, having a length relativelysmall in comparison to the overall length of outer shaft 50. Eachsection, such as section 55, is longitudinally slitted or striated,forming a plurality of longitudinal strips of outer shaft 50, such asstrips 56, 57 and 58 which are substantially equally spaced around thecircumference of the shaft and define longitudinal apertures or slits,such as slits 59, 60, and 61 in outer shaft 50. Similar slits, such asslits 69, '70, and 71, and strips, such as strips 66, 67, and 68, areprovided in section 54 of outer shaft 50.

The device of FIG. may be assembled by first precompressing outer shaft50 by the application at each end of inwardly directed forces. Sincesections 54 and 55 are weakened, to some degree, by the longitudinalslits or striations provided therein, the precompression results in theoutward bellowing or radial displacement of strips 56, 57, and 58, andstrips 66, 67, and 68, as

shown in FIG. 1. While still applying a precompression force sufficientto partially compress sections 54 and 55, inner rod 51 is fastened toboth ends of outer shaft 50. As described previously, a handle such ashandle 62 or an extender apparatus may be affixed to the proximal end ofthe device by suitable attachment to washer 52, and various coiled orpointed instruments, such as piercing tool 63 may be mounted on thedistal end of the device via attachment to washer 53.

Operation of the device shown in FIG. 5 is essentially similar to thatdiscussed hereinabove in relation to the device of FIG. 1. Duringinsertion into a pipe to be cleaned or unclogged, friction forcesbetween outer shaft 50 and the inner walls of the pipe tend torearwardly displace outer. shaft 50 with respect to inner central member51, since the latter is not subjected to the friction forces. Therearward longitudinal movement occasions the compression of section 54of outer shaft 50 and the simultaneous expansion of section 55 of theouter shaft. As shown in FIG. 6, compression of section 54 beyond itsprecompressed static condition results in the further outward bellowingor radial extension of strips 66, 67, and 68, to be discussed in moredetail hereinafter. Also depicted in FIG. 6 is section 55 of Duringwithdrawal of the device, friction forces between outer shaft 50 and theinner walls of pipe 90 tend to displace outershaft 50 in the forwarddirection with respect to inner. rod 51, resulting in the longitudinalcompression of section 55 and the longitudinal expansion of section 54of outer shaft 50. As shown in FIG. 7, compression of section 55 beyondits precompressed static condition results in the outward bellowing orradial expansion of strips 56, 57, and 58, in the same way that strips66, 67,and 68 are extended during insertion. The expansion of section 54results in the constriction or inward radial displacement of strips 66,67, and 68, in the same manner that strips 56, 57, and 58 awere inwardlydisplaced during device insertion.

In order to more fully appreciate the mechanism by which the variousstrips are radially displaced during compression and expansion ofsections 54 and 55, a single strip 80 typical of each of the strips 56,57, and 58, and 66, 67, and 68, is shown in edge view in FIG. 8A in itsstatic precornpressed condition. As can be seen therefrom, a certaindisplacement H, exists between the apex 81 of the strip and dashed line85, representing the outer surface of adjacent sections of outer shaft50. When a longitudinal compression force C and C is applied to each endof strip 80, as shown in FIG. 8B, the outer ends 82 and 83 of the stripare moved toward each other, and, as a consequence, the apex 81 of thestrip is radially extended to a displacement H from line 85 which isgreater than its previous displacement H When a longitudinal expansionforce E, and IE is applied to each end of strip 80, as shown in FIG. 8C,the outer ends 82 and 83 of the strip are moved apart from one another,and, as a consequence, the apex 81 of the strip is radially retracted toa displacement l-I from line 85, which is smaller than its previousdisplacement H Accordingly, the radial displacement of apex 81 of stripis controlled in response to longitudinal compression or expansion ofthe strip.

Returning now to FIG. 7, it can be seen that during withdrawal of thedevice from pipe 90, extended strips 56, 57, and 58 are brought intointimate contact with the interior walls of the pipe, and can thereforeadvantageously clean these walls. Each apex of strips 56, 57, and 58thus acts in a way similar to the claws 12 and 12' of FIGS. 1, 2, and 3in enabling cleaning of the pipe or engagement of a foreign objectlodged within the pipe.

If desired, the device of FIG. 5 may be modified to provide attachmentof outer shaft 50 to inner member 51 at only the distal endofthe device.In this event, slitted section 54 is not required, and the device neednot be precompressed during assembly. Since the proximal end of outershaft 50 is free to move relative to inner member 51, it should beapparent that compression of section 55 will occur, as previouslydescribed, during device withdrawal from a pipe. During deviceinsertion, slits 56, 57, and 58 will, in this configuration, remain in afully constricted condition, enabling easy device entry into the pipe.

The preceeding description of the operation of a snakelike device inaccordance with the principles of the invention has explained theautomatic action of the device in first retracting one or more clawsinto or toward the body of the device, thereby permitting easyinsertion, and then radially extending or outwarnlly dis- I placing theclaws from the device duringitswithdrawal from the pipe, thus enablingpositive engagement and removal of a clogging object. Since extensionand retraction of the claws are both automatic, and result from theadvantageous design of the device, it is apparent that the entire devicecan be attached to the front of a conventional snake-like apparatus, andthat the device will operate satisfactorily, and at an extended range.It should also be noted, however, that the device I can be operatedmanually, in which case an extender cannot be used. In manual operation,using the device of FIG. 1 as an example, the device may be gripped bothat its rear or trailing end, and simultaneously at the rearmost end ofsection 10a of outer shaft 10. By pulling the gripped sections together,loosely coiled section 10b is compressed, and the rearward displacementof section 10a tends to cause the elongation of section 100, therebyretracting or covering claws 12 and 12'. Thus, the device may beinserted into a confined space without impediment from the claws. In thereverse operation, the gripped sections are manually separated orexpanded, thereby displacing section 10a in the forward direction. As aresult, section 10c becomes compressed, and claws l2 and 12' are thusextended into position for obstruction engagement. Manual operation ofthe device of FIG. is achieved in an analogous fashion. While manualoperation may, on occasion, be desirable when the device is employed inthe plumbing field, this mode of operation may be necessary in certainsurgical procedures, where sufficient friction resistance to operate thedevice may not be offered by the interior duct or vessel walls, or wheresuch resistance may be harmful or injurious to the patient. By way ofexample only, and without limiting-the scope of the instant invention,which is defined by the appended claims, construction of the device ofFIG. 1 to the following dimensions and specifications may be foundadvantageous for use in the plumbing field:

Outer shaft 54; inch steel wire, coiled to 1 inch O.D., overall coiledlength 4 feet Section 10a: tightly coiled, length 2 feet, 8 inchesSections 10b and 100: loosely coiled, 14; inch space betweenconvolutions, length 4 inches Sections 10d and We: tightly coiled,length 4 inches Inner central member llz'seven thirty-seconds inchstranded steel wire, four strands at three thirty-seconds inch, length 4feet, 9 inches Claws l2 and 12': doubled back 9 inches portion of innercentral member 11, four claws spaced 90 apart around circumference ofouter shaft 10 Washer 13: A; inch steel, 1 inch O.D., A inch l.D.

Washer 14: .4: inch steel, 1 inch O.D., 95 inch I.D.

Many modifications and adaptations-of this invention will readily becomeapparent to persons skilled in the art. For this reason, it is intendedthat the invention be limited only by the appended claims. For example,in the preceeding description, outer shaft 10 has been described asfabricated from a single, continuous strand of wire having uniformmechanical characteristics. However, a plurality of wire=segments havingthe same -or different mechanical properties may be joined together tocomprise the length of wire necessary to form the outer coil, withoutdeparting from the spirit and.

scope of the invention. More particularly, it may be found advantageousto form outer shaft 10 from a segmented wire, so thatithe springconstants, defined as theratio of force required to produce a givendisplacement, of end sections 10b and 10c, are lower than the springconstant of center section 10a. By virtue of the selection of suchdifferent spring constants, both expansion and compression of sections10b and 100 require smaller longitudinal forces than does section 10a,and such compression and expansion will occur more readily. As a result,extension and retraction of claws Hand 12 is improved, especially insituationsin which friction forces between the device and the pipe orduct being cleaned are relatively small. It should be apparent thatdifferent spring constants for various sections of outer shaft l0 mayalso be achieved by suitably treating a single continuous strand ofwire, either before or after being coiled, as, for example, by removingthe temper from selected segments of the wire or coil.

What is claimed is: I

l. A device for cleaning the interior surfaces of an elongated pipecomprising,

a flexible rod for insertion into said pipe,

an outer shaft fitted around said rod, said outer shaft including meansfor enabling longitudinal movement of said shaft relative to said rod,and at least one claw extending from said device and having acontrollable radial displacement from said outer shaft in response tosaid longitudinal movement.

2. A device in accordance with claim i wherein said outer shaft isattached to said rod at at least one point.

3. A device in accordance with claim 2 wherein said device includes adistal end, and said point of attachment is said distal end of saiddevice.

4. A device in accordance with claim 3 wherein said outer shaft includesa helically coiled wire.

5. A device in accordance with claim 4 wherein said means enablinglongitudinal relative movement between said outer shaft and said rodincludes at least one loosely coiled section of said outer shaft havingconvolutions spaced apart one from the other.

6. A device in accordance with claim 5 wherein said at least one claw isattached to said rod and protrudes through a first one of said looselycoiled sections of said outer shaft.

7. A device in accordance. with claim 6 wherein said first one of saidloosely coiled sections is located toward said distal end of said'deviceand said at least one claw is attached to said rod at a point betweensaid first one of said loosely coiled sec-' tions of said outer shaftand said distal end of said device.

8. A device in accordancewith claim 3 wherein said outer shaft includesa hollow cylindrical length of plastic tubing.

9. A device in accordance with claim 8 wherein said means enablinglongitudinal relative movement between said outer shaft and saidflexible rod includes at least one section of said outer shaft having aplurality of longitudinal strips substantially equally spaced around thecircumference of said outer shaft and defining a plurality of slitssubstantially equally spaced around the circumference of said outershaft.

10. A device in accordance with claim 9 wherein each of said strips iscompressible into a curved surface having an apex, and f each of saidclaws includes said apex of one of said strips. ,W 11. A device inaccordance with claim 10 wherein a first one of said sections of saidouter shaft islocated toward said distal end of said 'deviee. v 12. Adevice in accordance with claim 1 wherein said outer shaft is attachedto said rod at a first point and at a second point,

said first pointincluding the distal end of said device" and psaid'second point including the proximal end of said device. 13. Adevice in accordance with claim 12 wherein said outer shaft includes ahelically coiled-wire.

14. A device in accordance with claim 13 wherein said means enablinglongitudinal relative movement between said outer shaft and said rodincludes first and second loosely coiled sections of said outer shafthaving convolutions spaced apart one from the other, a said firstloosely coiled section being located toward said distal end of saiddevice, an I said second loosely coiled section being located towardsaid proximal end of said device. 15. A device in accordance with claiml4 wherein said at least one claw is attached to said rod and protrudesthrough said first loosely coiled section of pipe, comprising tionedmeans includes at least one loosely coiled section of said spirallycoiled wire wherein adjacent convolutions are spaced apart one from theother.

said outer shaft, said at least one claw being attached to said rod at apoint between said first loosely coiled section and said distal end ofsaid device.

16. A device in accordance with claim l2 wherein 5 said outer shaftincludes a hollow cylindrical length of plastic tubing.

17. A device in accordance with claim 16 wherein said means enablinglongitudinal relative movement between said outer shaft and said rodincludes first and second sections of said outer shaft having aplurality of longitudinal strips substantially equally spaced around thecircumference of said outer shaft and defining a plurality oflongitudinal slits substantially equally spaced around saidcircumference said first section located toward said distal end of saiddevice said second section located toward said proximal end of saiddevice, and

said first and second sections being partially precompressed duringassembly of said device.

18. A device in accordance with claim 17 wherein each of said strips iscompressible into a curved surface having an apex, and

said at least one claw includes said apex of one of said strips. I

19. A device in accordance with claim 1 wherein said outer shaft isadapted for rearward longitudinal movement relative to said rod duringinsertion of 30 said device into said pipe, and

said claw is adapted for inward radial displacement from said outershaft in response to said forward longitudinal movement.

20. A device in accordance with claim 1 wherein said outer shaft isadapted for forward longitudinal movement relative to said rod duringwithdrawal of said device from said pipe, and a said claw is adapted foroutward radial displacement toward said outer shaft in response to saidrearward longitudinal movement.

21. A device for cleaning the inside surfaces of a a flexible rodforinsertion inside said pipe,

a tubular outer'member fitted around said rod and connected to said rodat at least one point,

said outer member having a circumference smaller than the insidecircumference of said pipe,

at least one claw attached to said device, said claw having acontrollable radial displacement from said rod, and

means for enabling longitudinal movement of said rod relative to saidouter member, said means operative for changing said radial displacementbetween said rod and said claw.

22. The device of claim 21 wherein said outer memher includes a spirallycoiled wire.

23. The device of claim 22 wherein said last mensaid claw is attached tosaid rod at a point between said first one of said loosely coiledsections and said distal end of said device,

said claw protrudes through said first one of said loosely coiledsections at a point rearward of said point of attachment,

said radial displacement between said rod and said claw being increasedduring withdrawal of said device from said pipe and said radialdisplacement between said rod and said claw being decreased duringinsertion of said device into said pipe.

25. The device of claim 21 wherein said outer mem ber includes a hollowlength of cylindrical tubing.

26. The device of claim 25 wherein said last mentioned means includes atleast one section of said cylindrical tubing having a plurality oflongitudinal strips substantially equally spaced around thecircumference thereof and defining a plurality of longitudinal slitssubstantially equally spaced around said circumference.

27. The device of claim 26 wherein said device includesa distal end,

said outer member is connected to said rod at said distal end of saiddevice,

a first one of said sections is located toward said distal end of saiddevice,

each of said strips of said first one of said sections is compressibleinto a curved surface having an apex forming said claw,

said radial displacement between said rod and said claw being increasedduring withdrawal of said device from said pipe.

28. The device of claim 25 wherein said last mentioned means includes atleast a first and a second section of said cylindrical tubing eachhaving a plurality of longitudinal strips substantially equally spacedaround the circumference thereof and defining a plurality oflongitudinal slits substantially equally spaced around saidcircumference,

said outer member is connected to said rod-at the distal end of saiddevice and at the proximal end of said device,v said first section islocated toward said distal end of said device and said second section islocated toward said proximal end of said device,

said first and second sections are partially precompressed duringassembly of said device,

each of said strips of said first section is compressible into a curvedsurface having an apex forming said claw, and

said radial displacement between said rod and said claw is increasedduring withdrawal of said device from said pipe and decreased duringinsertion of said device into said pipe.

29. A device for removing an obstruction from a confined space, saiddevice comprising an outer shaft of coiled wire,

an inner central member fastened to said outer shaft,

one or more claws attached to said inner central member and protrudingfrom said outer shaft, and

means including coils of said outer shaft enabling longitudinaldisplacement of said outer shaft relative to said inner central member,such that said claws are retracted into said outer shaft duringinsertion of said device into said confined space and extended from saidouter shaft during withdrawal of said device from said confined space,thereby enabling positive engagement of said obstruction. 30. A devicein accordance with claim 29 wherein said last mentioned means includesat least one loosely coiled section of said outer shaft.

31. A device in accordance with claim 30 wherein said device includes adistal end, said loosely coiled section is located toward said distalend of said device, and said claws are attached to said inner centralmember at a point forward of said loosely coiled section. 32. A devicefor removing an obstruction from a confined space, said devicecomprising a hollow outer shaft having at least one compressiblesection, an inner central member fastened to said outer shaft in amanner to allow longitudinal displacement of said shaft relative to saidinner central member by compression of said compressible section, and atleast one claw arranged to radially extend from said hollow outer shafta controllable distance, said distance controlled by said longitudinaldisplacement. 33. A device in accordance with claim 32 wherein saidouter shaft includes a hollow length of cylindrical tubing.

34. A device in accordance with claim 33 wherein said device,includes adistal end, said inner central member is fastened to said outer shaft atsaid distal end of said device, said compressible section includes aplurality of Iongitudinal strips spaced substantially equally around thecircumference of said outer shaft and defining a plurality oflongitudinal slits spaced substantially equally around saidcircumference, each of said strips is compressible into a curved surfacehaving an apex forming said claw, and said compressible section islocated toward said distal end of said device. as indicated in FIG. 1,enabling attachment of various devices surface having an apex, and

PRINTER'S TRIM LINI Column (SEAL) Attest:

Claim 34,

EDWARD M.FLETCHER,JR. Attesting Officer UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION Patent No. 3, 757, 375 Dated September 11,197} Inventor(s) Martin Strom It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

7, immediately following line /6, insert --outer shaft 50, which, uponlongitudinal expansion, becomes narrowed or constricted, so that theoutward radial displacement of strips 56, 57, and 58 due to theprecompression is reduced or eliminated, and the strips are broughtessentiall; into alignment with the adjacent portions of shaft 50. As aresult, the outer surfaces of outer shaft 50 are relatively uniform incircumference, with the exception of section 5 located toward theproximal end of the device, and the major portion of the device may thuseasily be insertedinto a pipe, such as pipe 90, having an innercircumference greater than the outer circumference of outer shaft 50.--.

lines 17 l9, delete --as indicated in FIG. 1,

enabling attachment of various devices surface having an apex, and--.

Signed and sealed this 19th day of March 1974.

C. MARSHALL DANN Commissioner of Patents USCOMM-DC 60376-F'69 U.S,GOVERNMENT PRINTING OFFICE I969 0 36fl-334,

1. A device for cleaning the interior surfaces of an elongated pipecomprising, a flexible rod for insertion into said pipe, an outer shaftfitted around said rod, said outer shaft including means for enablinglongitudinal movement of said shaft relative to said rod, and at leastone claw extending from said device and having a controllable radialdisplacement from said outer shaft in response to said longitudinalmovement.
 2. A device in accordance with claim 1 wherein said outershaft is attached to said rod at at least one point.
 3. A device inaccordance with claim 2 wherein said device includes a distal end, andsaid point of attachment is said distal end of said device.
 4. A devicein accordance with claim 3 wherein said outer shaft includes a helicallycoiled wire.
 5. A device in accordance with claim 4 wherein said meansenabling longitudinal relative movement between said outer shaft andsaid rod includes at least one loosely coiled section of said outershaft having convolutions spaced apart one from the other.
 6. A devicein accordance with claim 5 wherein said at least one claw is attached tosaid rod and protrudes through a first one of said loosely coiledsections of said outer shaft.
 7. A device in accordance with claim 6wherein said first one of said loosely coiled sections is located towardsaid distal end of said device and said at least one claw is attached tosaid rod at a point between said first one of said loosely coiledsections of said outer shaft and said distal end of said device.
 8. Adevice in accordance with claim 3 wherein said outer shaft includes ahollow cylindrical length of plastic tubing.
 9. A device in accordancewith claim 8 wherein said means enabling longitudinal relative movementbetween said outer shaft and said flexible rod includes at least onesection of said outer shaft having a plurality of longitudinal stripssubstantially equally spaced around the circumference of said outershaft and defining a plurality of slits substantially equally spacedaround the circumference of said outer shaft.
 10. A device in accordancewith claim 9 wherein each of said strips is compressible into a curvedsurface having an apex, and each of said claws includes said apex of oneof said strips.
 11. A device in accordance with claim 10 wherein a firstone of said sections of said outer shaft is located toward said distalend of said device.
 12. A device in accordance with claim 1 wheRein saidouter shaft is attached to said rod at a first point and at a secondpoint, said first point including the distal end of said device and saidsecond point including the proximal end of said device.
 13. A device inaccordance with claim 12 wherein said outer shaft includes a helicallycoiled wire.
 14. A device in accordance with claim 13 wherein said meansenabling longitudinal relative movement between said outer shaft andsaid rod includes first and second loosely coiled sections of said outershaft having convolutions spaced apart one from the other, said firstloosely coiled section being located toward said distal end of saiddevice, and said second loosely coiled section being located toward saidproximal end of said device.
 15. A device in accordance with claim 14wherein said at least one claw is attached to said rod and protrudesthrough said first loosely coiled section of said outer shaft, said atleast one claw being attached to said rod at a point between said firstloosely coiled section and said distal end of said device.
 16. A devicein accordance with claim 12 wherein said outer shaft includes a hollowcylindrical length of plastic tubing.
 17. A device in accordance withclaim 16 wherein said means enabling longitudinal relative movementbetween said outer shaft and said rod includes first and second sectionsof said outer shaft having a plurality of longitudinal stripssubstantially equally spaced around the circumference of said outershaft and defining a plurality of longitudinal slits substantiallyequally spaced around said circumference said first section locatedtoward said distal end of said device said second section located towardsaid proximal end of said device, and said first and second sectionsbeing partially precompressed during assembly of said device.
 18. Adevice in accordance with claim 17 wherein each of said strips iscompressible into a curved surface having an apex, and said at least oneclaw includes said apex of one of said strips.
 19. A device inaccordance with claim 1 wherein said outer shaft is adapted for rearwardlongitudinal movement relative to said rod during insertion of saiddevice into said pipe, and said claw is adapted for inward radialdisplacement from said outer shaft in response to said forwardlongitudinal movement.
 20. A device in accordance with claim 1 whereinsaid outer shaft is adapted for forward longitudinal movement relativeto said rod during withdrawal of said device from said pipe, and saidclaw is adapted for outward radial displacement toward said outer shaftin response to said rearward longitudinal movement.
 21. A device forcleaning the inside surfaces of a pipe, comprising a flexible rod forinsertion inside said pipe, a tubular outer member fitted around saidrod and connected to said rod at at least one point, said outer memberhaving a circumference smaller than the inside circumference of saidpipe, at least one claw attached to said device, said claw having acontrollable radial displacement from said rod, and means for enablinglongitudinal movement of said rod relative to said outer member, saidmeans operative for changing said radial displacement between said rodand said claw.
 22. The device of claim 21 wherein said outer memberincludes a spirally coiled wire.
 23. The device of claim 22 wherein saidlast mentioned means includes at least one loosely coiled section ofsaid spirally coiled wire wherein adjacent convolutions are spaced apartone from the other.
 24. The device of claim 23 wherein said deviceincludes a distal end, said outer member is connected to said rod atsaid distal end of said device, a first one of said loosely coiledsections is located toward said distal end of said device, said claw isattached to said rod at a point between said first one of said looselycoiled sections and said distal end oF said device, said claw protrudesthrough said first one of said loosely coiled sections at a pointrearward of said point of attachment, said radial displacement betweensaid rod and said claw being increased during withdrawal of said devicefrom said pipe and said radial displacement between said rod and saidclaw being decreased during insertion of said device into said pipe. 25.The device of claim 21 wherein said outer member includes a hollowlength of cylindrical tubing.
 26. The device of claim 25 wherein saidlast mentioned means includes at least one section of said cylindricaltubing having a plurality of longitudinal strips substantially equallyspaced around the circumference thereof and defining a plurality oflongitudinal slits substantially equally spaced around saidcircumference.
 27. The device of claim 26 wherein said device includes adistal end, said outer member is connected to said rod at said distalend of said device, a first one of said sections is located toward saiddistal end of said device, each of said strips of said first one of saidsections is compressible into a curved surface having an apex formingsaid claw, said radial displacement between said rod and said claw beingincreased during withdrawal of said device from said pipe.
 28. Thedevice of claim 25 wherein said last mentioned means includes at least afirst and a second section of said cylindrical tubing each having aplurality of longitudinal strips substantially equally spaced around thecircumference thereof and defining a plurality of longitudinal slitssubstantially equally spaced around said circumference, said outermember is connected to said rod at the distal end of said device and atthe proximal end of said device, said first section is located towardsaid distal end of said device and said second section is located towardsaid proximal end of said device, said first and second sections arepartially precompressed during assembly of said device, each of saidstrips of said first section is compressible into a curved surfacehaving an apex forming said claw, and said radial displacement betweensaid rod and said claw is increased during withdrawal of said devicefrom said pipe and decreased during insertion of said device into saidpipe.
 29. A device for removing an obstruction from a confined space,said device comprising an outer shaft of coiled wire, an inner centralmember fastened to said outer shaft, one or more claws attached to saidinner central member and protruding from said outer shaft, and meansincluding coils of said outer shaft enabling longitudinal displacementof said outer shaft relative to said inner central member, such thatsaid claws are retracted into said outer shaft during insertion of saiddevice into said confined space and extended from said outer shaftduring withdrawal of said device from said confined space, therebyenabling positive engagement of said obstruction.
 30. A device inaccordance with claim 29 wherein said last mentioned means includes atleast one loosely coiled section of said outer shaft.
 31. A device inaccordance with claim 30 wherein said device includes a distal end, saidloosely coiled section is located toward said distal end of said device,and said claws are attached to said inner central member at a pointforward of said loosely coiled section.
 32. A device for removing anobstruction from a confined space, said device comprising a hollow outershaft having at least one compressible section, an inner central memberfastened to said outer shaft in a manner to allow longitudinaldisplacement of said shaft relative to said inner central member bycompression of said compressible section, and at least one claw arrangedto radially extend from said hollow outer shaft a controllable distance,said distance controlled by said longitudinal displacement.
 33. A devicein accordance with cLaim 32 wherein said outer shaft includes a hollowlength of cylindrical tubing.
 34. A device in accordance with claim 33wherein said device includes a distal end, said inner central member isfastened to said outer shaft at said distal end of said device, saidcompressible section includes a plurality of longitudinal strips spacedsubstantially equally around the circumference of said outer shaft anddefining a plurality of longitudinal slits spaced substantially equallyaround said circumference, each of said strips is compressible into acurved surface having an apex forming said claw, and said compressiblesection is located toward said distal end of said device. as indicatedin FIG. 1, enabling attachment of various devices surface having anapex, and